Conventional shampoos typically comprise water and a dispersed or solubilized surface-active agent (e.g., a soap or detergent, a surfactant, or a combination of these agents). They may also include ingredients such as foam builders, foam stabilizers, emollients, viscosity modifiers, lubricants, humectants, preservatives, and fragrance. These shampoos are applied to the hair of the user and, in the course of such application; the shampoo is worked in a fashion that causes the shampoo to foam. The foams produced by these so-called “post-foaming” shampoos are relatively weak foams that quickly flatten.
Instant foaming shampoos are also known and typically comprise a propellant or blowing agent in addition to the above-named ingredients. They are dispensed from pressurized aerosol containers in the form of a rich foam lather for spreading by hand on the area to be cleaned. The foams produced by these instant foaming shampoos are also relatively weak, and deflate relatively quickly because of larger-sized bubbles, lower quality foam, and because the foaming action is not self-sustaining after dispensing.
It has now been found that the aforementioned problems and limitations of previous foaming shampoos are overcome by the present cleansing preparation which produces a high quality and self-sustaining foam immediately upon exposure to water without the need for physical agitation or rubbing.
Generally speaking, the present invention provides a cleansing preparation that foams upon contact with water, which comprises:                (a) at least one dry acid;        (b) at least one dry base; and        (c) at least one liquid film-forming cleansing agent,        
wherein, when the cleansing preparation is exposed to water, the acid(s) and the base(s) will react to form a gas and the cleansing agent(s) will form a liquid film, the gas and the liquid film will then interact to form or generate a foam (i.e., a mass of gas bubbles in a matrix of liquid film).
The present invention also provides a cleansing system which comprises a plurality of delivery particles, with each such delivery particle containing one or more of the above-named components of the inventive cleansing preparation, wherein, when the delivery particles are exposed to water, the particles will dissolve or break apart thereby releasing at least the acid(s) and the base(s). As noted above, the acid(s) and the base(s) will then react to form a gas, while the cleansing agent(s) will form a liquid film. The interaction of the gas and the liquid film will cause the formation or generation of a foam.
Other features and advantages of the invention will be apparent to one of ordinary skill from the following detailed description. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.